Fix 36Hour.#.ChancePrecipitation alignment

ATM there are 3 label 36Hour.#.ChancePrecipitation where # is 1, 2 or 3, and this is shown in middle of screen with `<right>590</right>`

idk what correct alignment is supposed to be but `<right>90</right>` seems to be more or less correct.

It worked when it was `<posx>590</posx>` but now it doesn't and I though I'd have a stab at fixing it.

See screenshot of bug.

![incorrect](https://f.cloud.github.com/assets/3521959/1774507/df2266b0-67f9-11e3-99e2-33705e7abecd.png)
And with this "fix"
![correct](https://f.cloud.github.com/assets/3521959/1774509/ecaa1152-67f9-11e3-9437-dc292edc1313.png)